Endo-bridge dilactones and preparation thereof



' uct can be purified by recrystallization.

United States Patent f ENDO-BRIDGE DILACTONES AND PREPARATION THEREOF John C. Sauer, Wilmington, Del., assignor to I..du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Application September 4, 1956 Serial No. 607,603 1 Q 16 Claims. (Cl. 260-343.3)

This invention relates to new compositions of matter audto a method for their preparation. More particularly this invention relates to new endobridge dilactones and to methods for their preparation.

When acetylenes are reacted with carbon monoxide in the presence of a catalytic amount of a cobalt carbony1,.as described in my copending patent application Ser. No. 549,155, filed November 25, 1955, as a 'continuation-in-patt of Ser. No. 432,599, filed May 26, 1954, now abandoned, there are obtained new dilactones corresponding to C (RR) O wherein R and R are hydrogen, haloaryl, alkoxyaryl, or hydrocarbon radicals free from non-aromatic unsaturation, and which show strong lines in the ultraviolet spectra in the region of 3300-4400 A., and yield suberic acids on hydrogenation over platinum in acetic acid. When acetylene is reacted with carbon monoxide in the presence of a catalytic amount of cobalt carbonyl, as described in my aforesaid patent application there is obtained [A -bifuran]- positions of matter and a method for their preparation.

A further object is to provide new dilactones having one to two endo-bridges and a process for their preparation. A still further object is to provide new endo-ring dilactones which can be reacted with diamines, such as hexamethylenediamine, to form polyamides. Other objects will appear hereinafter.

These and other objects of this invention are accomplished by providing new endo-bridge dilactonesv consisting of the adduct of fi'om 1 to 2 moles of a' conjugated diene with a dilactone having the formula C (RR') O wherein R and R are hydrogen, haloaryl, alkoxyaryl or monovalent hydrocarbon radicals free from non-aromatic unsaturation. In the new endo-bridge dilactones of this invention the conjugated diene has been. added by 1,4-

vaddition to the double bonded carbon atoms of one or.

provides the monoadduct and diadduct of conjugated dienes with the dilactone [A -bifuran]-5,5'-

dione.

The new endo-bridge dilactones ofthis invention are made by charging the dilactone into a reactor containing a reaction medium, if desired. To the. charge there is i then added from 1 to 2 moles of conjugated diene per mole of dilactone and the charge is then heated to between 75 and 225 C. The reaction mixture is'mainrained within the indicated range for at-least one hour. It is thereafter allowed to cool and the contents discharged. The desired product is recovered by filtration or by evaporation of the reaction medium. The prod- The examples which follow are submitted to illustrate and not to limit this invention.

2,859,220 Patented Nov; 4 1958 Example I .1

The trans dilactone [A -bifuran]-5,5-dione, prepared as described subsequently. (8.4 g.) and 13.8 g. of alpha-phellandrene (Z-methyl-S-isopropyl-1,3-cyclohexadiene) were heated to reflux temperature (175 C.). A vigorous reaction ensued which made further external heating unnecessary. After cooling and several days standing, crystals of the 1:1 adduct separated, which melted at 168-175" C., after washing with petroleum ether.

Example II I The trans dilactone of Example I (10 g., 0.06 mole), butadiene (20 g., 3.7 moles), dioxane (200 ml), and an inhibitor ,(p-nitroso-N,N-diethylaniline, 0.14 g.) were heated at C. in a closed steel vessel .for- 16 hours, after ,which 4.1 g. of undissolved dilactone remained. The solution was freed of its solvent 'under're'duced pr; es sure, leaving 5.9 g. (75 of a. solid, soluble in emote form, M..P. 106-110" C. Recrystallizationfroni 'eth'yl acetate-petroleum ether gave', white, waxy needles, 1 M. P. 109.5 C. of the 1:1 adduct.

Analysis.-Calcd for C H O C, 66.05%; H, 4.62%; M..W., 218. 7 Found: C, 65.95%, 66.15%,H, 4.66%,

Infraredanalysis: 3.2,. (=CH), 3.4..- ..uiaedf n),

5.5a. and 5.6 1. (carbonyls of two lactone rings), 5.9/J. (exocyclic double bond), 6.5g. (conjugated unsaturation).

1 :1 adduct of 1,3-butadiene with thedtrans dilactone [A t m -biturank 10119 Y The splitting of the carbonyl band in the infared into two peaks demonstrates that one of thedoublebonds adjacent to the carbonyl group acted as the dienophile, since if the central double bond has reacted, the two lactone rings would have remained identical.

Example III The trans dilactone of Example I (25 g., 0.15 mole), 2,3-dimethyl-1,3-butadiene (13 g., 0.16 mole, containing hydroquinone), and dioxane (200 ml.), were heated at C. for 16 hours in'a closed steel vessel. The product was filtered to give 10.4 g. of a pale yellow solid, M. P. 151-154 C. Concentration of the filtrate gave an additional 20.9 g. of the 1:1 adduct bringing the total yield to 31.3 g. (84% The second crop was recrystallized from, ethyl acetate-petroleum. ether, M. P. 153-- 154 C.

use;

closed steel vessel. .17 :g. 2 3-% -at 50% conversion) of the diadduct from 1:1 adduct of 2,3-d1'meth yl-L3-hutadiene with the trans dilactone [AM'G -b1furan]-5.5-d1one EiampleIV The cis form ot the dilactoneof Example I (24.2 g., 0.15 mole), 2,3-dimethyl-l,3-butadiene (13 g., 0.16 mole, containing hydroquinone), and dioxane (200 ml.) were heated in a steel tube for 16 hours at 150 C. The product was filtered to give 8.6 g. (24%) of a white solid corresponding in structure to a 1:1 adduct below. Infrared analysis showed carbonyls at 5.50 and 5.65,u, 5.88;]. exocyclic double bond), 6.48 (double bond in lactone rin 3l4u"(satur'ated CH). The product was thus similar to that of theproduct of Examples 11 and i=1 meet or 2g3-dimethly L3- hutadlene with the cis dilactone v [A -biIuran]-5,5'-dione wasf iniich less soluble'than' the l ot s bn add ct .q x mp I m trans d ;was recrystallized from. ethyl acetate,

The filtrate from the reaction mixture was concenti'at'ed by distillation under reduced pressure 'to give 19.1 g. (53%) of a'pale yellow solid, which melted at 156f C.,

after recrystallization, from e'thyl facetate. -m-fcemfpigund'di not'depr'ess the rrielting point ofthe'adduct of Exam III and must therefore 'be the adduct from the acto'nerIt is assumed that this arose from thermal isomerization of the adduct from the cis dilactone. Example V A solution of 15.1g. (0.061'fiiole) of the monoadduct of Example III from the trans dilactone and 5.3 g.

(0.065 mole) of '2, 3-dimethyl-1,3-butadiene in 200 ml.

of dioxane was heated at 150 C. for 19 hours in a Filtrationiof the product separated solution which on concentration gave 7.6 g. of reed starting material. The diadduct was recrystalhzrd from methyl ethyl ketone melted at244 C.

737%;N.W., 328." Found: C, 72I67%,'72. 1'5 H, 7.26%, 7.00%; N. W., 314.

The completely symmetrical compound exhibits the expected infrared spectrum. There is no absorption band for the central double bond and the lactone carbonyl gives a sharp absorption peak at 5.62

Example VI The trans dilactone of Example I (20 g., 0.12 mole), 2,3 dimethyl 1,3 butadiene (22 g., 0.27 mole), and dioxane (200 ml.) were heated at 175 f C. for 18 hours in a closed vessel. The sparingly soluble diadduetffrom the trans dilactone (9.2 g., 23%) separated from" the solution and melted at 240-243 C. From the filtrate:

was obtained 20.1 g. (67%) of the-monoadduct of Example IH, M. P. 154156 C. after recrystallization from ethyl acetate. I

Example VII 7 trans-dilactone of Example I (l6.4g.,A0.-l0rlniole;),

l,3-butadienej 25, g., 0.64 mole),'and dioxane (200 ml.) were heated at 200 C. .for 1 7- hours... Thediadduct of 1,3-butadiene fromthe trans di1actone.;(1.-flg-z) separated from the; solution. ,Another ,2.3 g. 'was-;obtained*from' [the mother liquor bringingitheyield tof14%. The new dilactone .could 'be recrystallized from feitherrmethyl ethyl ketone or ethyl acetate and melted at 232". C.

Dladduct of 1,3-butadiene with the trans dilactone lA m bifuran]-5,5-dione Anal sis-cued for 0 11 50.: c, 70.57%;

5. 2%. Found: c, 70.44%; H, 5.84%.

Example V711 The monoadduct of Example IV 'fromzthefcis' dilac'tone (7.4' g.,:'0.045 mole), M. 'P. 174-178' C.'-washeated'at 150 C. with 2,3-dimethyl-1,3-butadiene (3.7 g.,'0.045

-mole) indioxane (2001111.) for-19'hours; "Ihe'resulting.

solutionwas: eyapora'ted to dryness 'and' the re'siduei tri- 'turated with chloroform andpetroleumether'to. g'iv'e:0:8'g. 7 .'(11%) or a white solid, whichaftef'recrYstallization M. .W., 246. "Found: C, 6'8;28%,'"68.51%;' H; 5.88%,

Infrared analysis-3.45;; (saturated CH), 5.5;tiand 5.7a (carbonyls of two lactone'rings),"5.85u (exocyclic double'bond), 6.1 C=C From the mother liquor, there were recovered 2.9 g. (39%) of the startirighaaterial. v

The new adduct is probably related tojthemonoadduct from the cis dilactone by cis-trans isomerism at the points of junction of the fused rings (i. e., of the decahydronaphthalene type) i In the-examples, butadiene, 2,3-dimethylbutadie'ne, and alpha-phellandrene have' been used as'the conjugated dieneflt is to be understood that in place of these I conjugated diene hydrocarbons, other conjugated dienes can 'be employed. Examples areconjugated' diolefinic chlorides, ,such as '2-ch1oro'-1,3-butadiene, lower. salkyl conjugated diolefinic and niolefinic esters, such as methyl 2,4-hexadienoate, 4 ethyl 1,3 hexadienoate and;2,4,6- heptatrienoate, and aliphatic and cycloaliphatic conjugated diolefins and triolefins 'such as alpha-terpinene, 'cyclopentadiene, hexachlorocyclopentadiene, 1,3,5- hexatriene, and the like, The conjugated dienes are preferably of from 2 to.3 conjugated 1000 atmospheres for 14-17 hours. The product was filtered and the brown solid was extracted with ethyl acetate for 24 hours. The extract was permitted to crystallize and the crystalline material was separated, and dried at room temperature. There-was obtained 20 g. of the unsaturated dilactone, C H O M. P. 229 C. after several recrystallizations from acetic acid.

The [A -bifuranl-5,5'-dione exists in the form of two structural isomers, which yield suberic acid when hydrogenated with platinum in acetic acid. The normal or low melting form, 230-237 C. is the trans form and the high melting form, 240248 C. is the cis form. The formulae of these structural isomers of [A bifuranl-5,5'-dione are as follows:

Low melting or trans form 0 O HC|=CH H6 (3H High melting or cis form The dilactones used in preparing the compounds of this invention are the products obtained by reacting an acetylene with carbon monoxide in the presence of a cobalt carbonyl catalyst, as disclosed and claimed in my copending application, U. S. Ser. No. 549,155, filed November 25, 1955. v

The cobalt carbonyl catalyst may be made directly by reaction of carbon monoxide with the metal in active form, as described in the J. Am. Chem. Soc. 70, 383-6 (1948).

The acetylenes used in preparing these dilactones correspond to RCECR', in which R and R are hydrogen, alkoxyaryl, especially where the alkoxy group is of not more than 12 carbon atoms and the aryl radical is hydrocarbon of not more than 10 carbon atoms, haloaryl especially chloroaryl where the aryl radical is hydrocarbon of not more than 10 carbon atoms, or monovalent hydrocarbon radicals free from non-aromatic unsaturated, especially of not more than 12 carbon atoms, e. g., alkyl, especially short chain alkyl, i. e., containing not more than seven carbon atoms, aryl, especially where the aryl radical is hydrocarbon of not more than 10 carbon atoms, aralkyl, especially of not more than seven carbon atoms, or cycloalkyl, particularly of not more than seven carbon atoms. Examples of such radicals are methyl, ethyl, octyl, decyl, dodecyl, phenyl, tolyl, xylyl, naphthyl, benzyl, cyclohexyl, methylcyclohexyl, chlorophenyl, methoxyphenyl, ethoxyphenyl, decylphenyl, dodecyloxyphenyl, dodecyloxynaphthyl, and the like. Examples of such acetylenes are acetylene, methylacetylene, 2 -decyne, phenylacetylene, naphthylacetylene, p-chlorophenylacetylene, p-ethoxyphenylacetylene, 'p-decyloxyphenylacetylene, benzylacetylene, cyclohexylacetylene, inethylcyclohexylacetylene, etc.

By employing such substituted acetylenes, there are obtained dilactones corresponding in molecular formula to C (RR') O the radicals R and R corresponding to the Zerewitinofi method, Ber. 40, 2026 (1907); J. Am.

the substituents attached to the triply bonded carbon in the acetylene reactant, i. e., R and R in RCECR'. Thus, as shown by the'aforementioned Sauer application, there are prepared the following dilactones:

soluble in hot acetone and dimethyl formamide.

Chem. Soc. 49, 3181 (1927). Specific organic reaction media are isooctane, toluene, acetonitrile, acetone, "ethylacetate, dioxane, cyclohexanone, xylene, benzene, etc.

The unsaturated dilactones can be represented by the general formula where one of the ring doubly bonded carbon atoms has its free valence satisfied by R and the other of the ring doubly bonded carbon atoms has its free valence satisfied by R, with R and R being defined as aforesaid with respect to the acetylenic reactants.

Substitution of the hereinbefore listed dilactones for the [A -bifuran]-5,5'-dione of the examples in the process of the examples leads to the obtainment of the corresponding endo-bridge dilactones. In this manner monoand diadducts of alpha-phellandrene, 1,3-butadiene, 2,3dimethylbutadiene and other conjugated dienes are obtained with the hereinbefore listed dilac-' tones. Thus, the mono and diadducts of alpha-phellandrene, 1,3- butadiene and 2,3-dimethylbutadiene with [A -bidiethylfuran]-5,5-dione, [A -bichlorophenylfuran] 5,5 dione, EA -bi-o-methoxyphenylfuran]-5,5-dione, and with the other dilactones are obtained.

Although not essential, an organic liquid reaction medium is generally used in effecting the condensation between the dilactone.C (RR) O and the diene. Examples of such media are benzene, toluene, dioxane, ethyl acetate, and the like. The amount of reaction medium is not critical and it can vary from an amount equal in weight to the combined weights of the dilactone and diene. In general, however, an amount is used which is ten or more times the amount of dilactone and diene.

The time of reaction depends on the nature of the reactants employed, i. e., dilactone and diene. Usually the reaction is carried out for at least 10 hours. Preferably, however, the reaction is carried out for from 14 to 30 hours.

In the condensation, temperatures are used in the range of to 220 C. However, best results from the standpoint of yield of desired products are realized in the more restricted range of to 200 C. and this embraces the more generally used temperatures.

As illustrated by the working examples, the process by which the products of this invention are obtained can be carried out at atmospheric pressure or at super-atmospheric pressures corresponding to the autogenous pressure of the reactants under the temperature conditions used.

The endo-bridge dilactones of this invention are also useful for the preparation of polymers, as by reaction with polyamines, as described below:

To 0.72 g. of the product of Example HI there was added 0.34 g. of hexamethylenediamine and the mixture was heated-in a sealed, evacuated tube'at 100 C. for 1.5

hours.- The product was .a pliable resin, which' was inproduct is useful for coating flexible and rigid substrates.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope" thereof, it isto' be understood that this invention is not limited to the specific embodiments and wherein one free valence of each ring is satisfied by R and the other free valence of each ring is satisfied by R, said R and R being selected from the class consisting of hydrogen, alkoxyaryl where the alkoxy group is of not more than 12 carbon atoms and the aryl radical is hydrocarbon of not more than 10 carbon atoms, haloaryl where the aryl radical is hydrocarbon of not more than 10 carbon atoms, and monovalent hydrocarbon radicals, free from non-aromatic unsaturation, of not more than 12 carbon atoms, said endobridge dilactone having the doubly bonded carbon atoms of from one to both of the dilactone rings each joined to one mole of said conjugated diene by 1,4-addition.

2. An endo-bridge dilactone which consists of the adduct of from one to two moles of a conjugated diene of 4 to 10 carbon atoms and one mole of the unsaturated dilactone represented by the structural formula 0 O=C C=O c=0 Hc( 3H HccH said endo-bridge dilactone having the doubly bonded carbon atoms of from one to both of the dilactone rings each joined to one mole of said conjugated diene by 1,4- addition. I

3. An endo-bridge dilactone which consists of the adduct of from one to two moles of a conjugated diene of 4 to lq carbon atoms and one mole of the unsaturated dilactone represented by the structural formula said endo-bridge dilactone having the doubly bonded carbon atoms of fromone to both of the dilactone rings each joined to onemole of said conjugated diene by 1,4- addition. 7

4. An endo-bridge dilactone which consists of the adduct of from one to two moles of a conjugated diene hydrocarbon of 4 to 10 carbon atoms and one mole of the unsaturated dilactone represented by the structural formula said endo-bridge dilactone having the doubly bonded carbon atoms of from one to both of the dilactone rings each joined to-one mole of said conjugated diene hydrocarbon by 1,4-addition.

5. An endo-bridge dilactone which consists of the adduct of from one to two moles of a conjugated diene hydrocarbon of 4 to 10 carbonatoms' and c te moleofthe unsaturated dilactone represented by the structuralfformu1a 1 H(] on 0 said endo brid'ge dilactone having the doubly bonded carbon'atotns of from one to both of the dilactone ringsf each joined to one mole of said conjugated diene hydro carbon by 1,4-addition'; v j 6. An'endo-bridge dilactone which consists of the adduct of one mole of'a conjugated diene hydrocarbon of 4 to 10 carbon atoms and one mole of the unsaturated dilactone represented by the structural formula" V HO oH'Ho on I 1 said endo-bridge dilactone having the doubly bonded carbon atoms of solely one of the dilactone rings joined to one mole of said conjugated diene hydrocarbon by 1,4-addition. 7

7. An endo-bridge dilactone which consists of the adduct of one mole of a conjugated diene hydrocarbon of 4 to 10 carbon atoms and one mole of the unsaturated 8. The endo-bridge dilactone which consists of the? 1,4-addition adduct of one mole of 2-methyl-5-isopropyl-. 1,3-cyclohexadiene and one mole of the unsaturated dilactone represented by the structural formula HC-TCH said endo-bridge dilactone being represented by thestructural formula 9. Process for preparing an endo-bridge dilactone.

which comprises heating and reacting at a temperature within the range of v75 to 225 C., from one to two moles of a conjugated diene of 4 to 10 carbon atoms per mole of unsaturated dilactone represented by one of the structural formulas selected from the class consisting-of wherein one free valence of each ring is satisfied by R and the other free valence of each ring is satisfied by R, said R and R being selected from the class consisting of hydrogen, alkoXyaryl where the alkoxy group is of not more than 12 carbon atoms and the aryl radical is hydrocarbon of not more than 10 carbon atoms, haloaryl where the aryl radical is hydrocarbon of not more than 10 carbon atoms, and monovalent hydrocarbon radicals, free from non-aromatic unsaturation, of not more than 12 carbon atoms, and isolating as the resulting product an endo-bridge dilactone which conststs of the 1,4-addition adduct of from one to two moles of said conjugated diene and one mole of said unsaturated dilactone.

10. Process for preparing an endo-bridge dilactone which comprises heating and reacting at a temperature within the range of 75 to 225 C., from one to two moles of a conjugated diene of 4 to 10 carbon atoms per mole of unsaturated dilactone represented by the structural formula I l l HG hi1 HC CH and isolating as the resulting product an endo-bridge dilactone which consists of the 1,4-addition adduct of from one to two moles of said conjugated diene and one mole of said unsaturated dilactone.

11. Process for preparing an endo-bridge dilactone which comprises heating and reacting at a temperature within the range of 75 to 225 C., from one to two moles of a conjugated diene of 4 to carbon atoms per mole of unsaturated dilactone represented by the struc' tural formula H( 3 and isolating as the resulting product an endo-bridge dilactone which consists of the 1,4-addition adduct of from one to two moles of said conjugated diene and one and isolating as the resulting product an endo-bridge.=

dilactone which consists of the 1,4-addition adduct of from one to two moles of said conjugated diene hydrocarbon and one mole of said unsaturated dilactone.

13. Process for preparing an cndo-bridge dilactone as set forth in claim 12 which comprises heating and reacting at a temperature of to 225 C. one mole of said conjugated diene hydrocarbon of 4 to 10 carbon atoms per mole of said unsaturated dilactone and isolating as the resulting product an endo-bridge dilactone which consists of the 1,4-addition adduct of one mole of said conjugated diene hydrocarbon and one mole of said unsaturated dilactone; r

1.4. Process for preparing an endo-bridge dilactone which comprises heating and reacting at a temperature within the range of 75 to 225 C. from one to two moles of a conjugated diene hydrocarbon of 4 to 10 carbon atoms per mole of unsaturated dilactone represented by the structural formula 0 HG OH O=C at 6:0 I I HCCH 0 and isolating as the resulting product an endo-bridge dilactone which consists of the 1,4-addition adduct of from one to two moles of said conjugated diene hydrocarbon and one mole of said unsaturated dilactone.

15. Process for preparing an endo-bridgedilactone as set forth in claim 14 which comprises heating and reacting at a temperature of 75 to 225 C. one mole of said conjugated diene hydrocarbon of 4 to 10 carbon atoms per mole of said unsaturated dilactone and isolating as the resulting product an endo-bridge dilactone which consists of the 1,4-additi0n adduct of one mole of said conjugated diene hydrocarbon and one mole of said unsaturated dilactone. t

16. Process for preparing an endo-bridge dilactone which comprises heating and reacting at a temperature within the range of 75 to 225 C. one mole of Z-inethyl- 5-isopropyl-1,3-cyclohexadiene per mole of unsaturated dilactone represented by the structural formula No references cited. 

1. AN ENDO-BRIDGE DILACTONE WHICH CONSISTS OF THE ADDUCT OF FROM ONE TO TWO MOLES OF A CONJUGATED DIENE OF 4 TO 10 CARBON ATOMS AND ONE MOLE OF AN UNSATURATED DILACTONE REPRESENTED BY ONE OF THE STRUCTURAL FORMULAS SELECTED FROM THE CLASS CONSISTING OF 